The present invention relates to a film deposition method suitable to produce functional films.
Various functional films (functional sheets) including gas barrier films, protective films, and optical films such as optical filters and antireflection films are used in various devices including optical devices, display devices such as liquid crystal display devices and organic EL display devices, semiconductor devices, and thin-film solar batteries.
These functional films have been produced by film formation (thin film formation) through vacuum deposition techniques such as sputtering and plasma-enhanced CVD.
Continuous deposition of a film on an elongated substrate is preferred for efficient film formation with high productivity by a vacuum deposition technique.
A typical film deposition device known in the art for conducting such film formation is a roll-to-roll film deposition device using a feed roll having an elongated substrate (a web of substrate) wound into a roll and a take-up roll in which the substrate having a film formed thereon is wound into a roll. This roll-to-roll film deposition device continuously forms a film on the elongated substrate in a film deposition compartment as the substrate travels from the feed roll to the take-up roll on a predetermined path including the film deposition compartment for depositing a film on the substrate, with the substrate fed from the feed roll in synchronism with the winding of the substrate having the film formed thereon on the take-up roll.
As such a roll-to-roll film deposition device, a device is also known in which a cylindrical drum is provided in a vacuum chamber, film deposition means such as an electrode and a reactive gas supply means are provided at positions facing the peripheral surface of the drum, and film deposition is continuously performed by the film deposition means as a substrate is traveling on the peripheral surface of the drum.
For example, JP 2004-95677 A describes a substrate treatment device which includes a feed roll (delivering roll) for feeding a flexible substrate to treatment compartments, the treatment compartments where the surface of the fed substrate is treated and a take-up roll on which the treated substrate is wound, and in which a drum (pass roll) is provided to make the substrate pass through the treatment compartments while contacting the peripheral surface of the drum, the treatment compartments are disposed in a circumferential direction of the drum, and differential compartments (differential evacuation compartments) are provided so as to be adjacent to the treatment compartments and are evacuated.
JP 2000-239849 A describes a continuous plasma CVD in which a continuous substrate (flexible base) which is traveling along a rotary drum disposed in a vacuum chamber is exposed to plasmas including RF plasma from an RF generator and microwave plasma to continuously form a thin film. JP 2000-239849 A also describes that the RF generator connected to the rotary drum applies a bias potential to general the plasma, thereby performing film deposition by plasma-enhanced CVD.